Exporting Data from Mathematica with commas

I am exporting data from mathematica in this manner to a file with "dat" extension.

numbercount=0;
exporttable =
   TableForm[
    Flatten[
     Table[
      Table[
       Table[{++numbercount, xcord, ycord, zcord}, {xcord, 0, 100, 5}], 
      {ycord, 0, 100, 5}], 
     {zcord,10, 100, 10}],
    2]];
Export["mydata.dat", exporttable]

Now what happens is the "mydata.dat" file the output appears like this

1  0   0   10
2  5   0   10
3  10  0   10  and so on

But I want the data to appear like this in the "mydata.dat" file.

1, 0,  0,  10
2, 5,  0,  10
3, 10, 0,  10  and so on

If you observer I want a comma after every first,second and third number but not after the fourth number in each line.

I have tried this code it inserts the commas between the number But it takes a long time to run as I have huge amounts of data to be exported.I also feel that someone can perhaps come up with a 开发者_高级运维better solution.

numbercount=0;
exporttable =Flatten[
              Table[
               Table[
                Table[{++numbercount, xcord, ycord, zcord}, {xcord, 0, 100, 5}], 
               {ycord, 0, 100, 5}], 
              {zcord,10, 100, 10}], 
             2];
x = TableForm[Insert[
              exporttable[[i]], ",", {{2}, {3}, {4}}], {i, 1, Length[exporttable]}];
Export["mydata.dat", x]

Have you tried exporting it as a CSV file? The third parameter of Export is file type, so you'd type

Export["mydata.dat", x, "CSV"]

To add to this, here is a categorical list and an alphabetical list of the available formats in Mathematica.

As an aside note, please note that you can build your list with only one Table command, and without explicit index variables:

exporttable1 =  MapIndexed[Join[#2, #1] &, 
                                Flatten[Table[{xcord, ycord, zcord}, 
                                                {zcord, 10, 100, 10}, 
                                                {ycord, 0, 100, 5}, 
                                                {xcord, 0, 100, 5}], 2]]

exporttable1 == exporttable
(*
-> True
*)